I suspect you are right. I think the questions have the same intended scope, and that answers to the proposed original could be applied to the proposed duplicate.
However, I do think I can understand why others might disagree: With Nigel's edit, his question addresses a more specific context than the original one does. It could hypothetically be read as "Why did the King James Bible chose to consistently translate the greek olam into everlasting and aionos into eternal?" instead of "What is the usual difference between everlasting and eternal now?" Perhaps there is a difference in meaning that applied in Early Modern English that is no longer used, and if so, that point of interest may encourage separate sets of answers to each question.
We are usually pretty forgiving about the whole duplicate thing, if somebody can adequately explain why their question needs a different answer than the original. The duplicate policy mostly exists so that all answers regarding a particular issue can be found in one place, but if there are two separate issues that need to be answered differently, then it makes little sense to close one question as a duplicate as the other, even though they may seem to be the same at face value.
Although I suspect it is a duplicate, I would personally at least like to know which matter Nigel J is interested in knowing before deeming it a duplicate. If it is the issue explained in second half of the question, perhaps somebody could make a clarifying edit could be applied to show that the question is not a duplicate. However, if he really does just want to know the general difference between the two words is, then I would recommend keeping it closed as a duplicate
Also, due to the nature of the question, I also only mean to address this matter from the matter of if it is, or is not, a duplicate. Determining if it should, or should not be closed for some other reason is a much more complicated matter, due to the half dozen or so closure reasons that may apply. Naturally, if there is some other reason it should be closed, it should be closed regardless of if it is a duplicate or not.